[time-nuts] FTS4060 C Field Time Constant

Brooke Clarke brooke at pacific.net
Mon Feb 28 20:41:00 EST 2005


Hi:

The C field has been set at 570 since the night of 20 Feb. and I haven't seen any drift, but the average of 1,000 time interval measurements from the GPS 1 PPS to the 1 MHz output has quite a bit of wandering which I'm convinced is caused by something related to the GPS.   One way to see that is to also look at the LORAN-C data which is on the bottom of the plot.  The gap in the LORAN-C data was caused by the Middletown station shutting down while they switched over to the solid state power amplifier.

Another clue that it's GPS based is to notice that the time of day when the big changes occur are about the same.  The major lines are each at midnight.  Maybe it's related to which GPS satellites are being used?
I have the receiver set for the 4 highest and a 30 degree elevation mask, but maybe should increase the elevation mask even higher?

http://www.pacificsites.com/~brooke/pdf/sn1227_CF570.pdf

Have Fun,

Brooke Clarke, N6GCE

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